The present invention relates to a colorimetric determination of biological molecules or organic compounds that are substrates for NAD(P)-linked dehydrogenase enzymes. In addition, this invention is useful for the colorimetric determination of the levels or concentrations of NAD(P) linked dehydrogenase enzymes. This invention is also useful in the direct colorimetric measurement of NAD(P) and NAD(P)H.
This invention reduces the amount of color that is generated when the substances are assayed which cause color to be generated in the presence of a chromogen. This reduction in color generation greatly expands upward the possible concentration of substance that can be measured. This makes possible the determination of the concentration of a wide variety of medical and industrial substances without dilution of the aqueous sample containing that substance to lower the concentration of the substance to be measured. This reduction in color that is generated in response to NADH production into a visible (or readable) range, is unknown in the prior art.